UPDATED 3/31/11 9pm EST
I am sure there are more I missed. Thanks to those of you who told me of others, I will post the others as soon as I find pictures.
JAKQBanba dressed as an old lady.
Goggle FiveMiki dressed as a 'Prince' doll to contact a 'Princess' doll.
JetmanRaita from Jetman dressed as a geisha in order to fool a monster who was stealing young women's voices.
OhrangerIn Ohranger, Shouhei crossdesses as a woman as a secret undercover mission.
CarrangerA character who only appeared in Episode 23, a princess crossdresses as a construction worker in order to fool a monster. She was in cahoots with Naoki/Blue Racer.
GoGoVGoGoFive's Nagare crossdressed for a mission.
Gaoranger
Gao Black crossdressed in a wedding dress to fool Wedding Dress Org.
AbarangerYukito (AbareBlue) crossdressed in an episode.
Dekaranger In Dekaranger 26, he dressed up as a woman to get into an illegal fighting club - originally, he was there with Hoji, but was recognized as a Deka, and therefore had to dress differently to get in and not be recognized. And in Dekaranger 45, he dressed up as Swan to help get rid of a someone that was bothering her. Testu crossdresses to fool an Alienzer.
Magiranger vs. DekarangerHikaru and Tetsu crossdress to fool one of the monsters.
BoukengerThree of the boys crossdressed in a retelling of Cinderella that Natsuki did in Ep 26.
Sakura crossdressed as a prince. Natsuki and Eiji were the only ones who didn't in that episode.
I forgot that in the last episode, Morio disguised as Sakura as she went into space with Akashi.
Go-Onger All the males were rendered frozen and the girls hid them from the bad guys by dressing them as women as mannequins. Episode 38.
Hanto dressed as an old woman's granddaughter, but it then turned out that the woman was a scientist from another dimension. Episode 27. Sousuke dresses up as an old lady or "Ba-san" in one episode when they were wearing disguised in the next episode, 28.
ShinkengerRyuunosuke (spelling wrong) crossdressed as a bride in Episode 8.
In their post show special, they all crossdressed. I haven't seen the special so I do not know the purpose. Mako and Kouta as school boys, and the boys as girls, Genta was the only one who didn't wear his ranger-color of the boys, he wore pink.
GoseigerHyde dressed as Nanami/Hurricane Blue for the Teamup special (they showed old teamups, by half-hour) that aired an hour before Goseiger.
Eri as AbareKiller, for the same special, that aired for a couple of weeks.